Bayer Leverkusen have signed Germany international Sven Bender from Borussia Dortmund for a reported €15 million fee.

Bender, 28, will join his twin brother Lars at Leverkusen after signing a four-year contract. The pair last played together at club level at 1860 Munich in 2009.

The versatile midfielder leaves BVB after eight largely successful years, and as one of the key members of the back-to-back title winning team earlier this decade.

Bender said on the official BVB website: "Only a few days ago, I approached [CEO] Aki Watzke and [sporting director director] Michael Zorc to ask a personal favour. After eight years at Dortmund, I wanted them to grant me a new challenge."

Having only played in eight competitive matches last season, Bender said he was looking for more game time and was thankful that Dortmund "respected my will despite their wish to keep me."

In a lengthy statement, Dortmund said they had wanted to keep Bender but allowed him a move because of his contribution to the club.

"To be honest, if it had not been 'Manni' [Bender's nickname] with his BVB career expressing this wish, we would have never said yes," Watzke said.

Zorc added that Dortmund are losing a "real leader."

Leverkusen sporting director Rudi Voller said in a statement on Bayer's official website: "We are delighted that Sven has decided to join us. He's an extraordinary experienced and versatile player, who most recently at Dortmund demonstrated his class at the centre-back position."

New Leverkusen head coach Heiko Herrlich praised Bender's "mentality and team spirit."

He said: "This makes him the ideal leader on and off the pitch. Just like his brother Sven he stands for a certain type of player every team needs: A high footballing level, relentless, giving his all for the collective. It's just great to have both Benders on one team."

Bender played in 224 competitive matches for Dortmund, the club he joined from 1860 Munich in 2009. He won two Bundesliga titles and two German cups with BVB, and also played in the 2013 Champions League final.

In a career overshadowed by several injuries, he has so far also won seven caps for Germany and was part of the squad which won the silver medal at the 2016 Olympics.